Film Finesse

Films
play key role in the future of high-performance pressure-sensitive tapes.

The
world market for pressure-sensitive adhesive tapes is expected to continue
growing 5% per year through 2010 and be valued at $25 billion, according to the
Freedonia study World Pressure Sensitive Tapes. Projected
growth in tape production will generate demand for 3 billion kg of raw
materials in 2010, including adhesives and various backing substrates. The
growing global economy will create opportunities in developing countries like China and India,
which will outpace the U.S.
in terms of tape consumption. In addition, the cost and performance advantages
of pressure-sensitive adhesive tapes will enable these products to capture an
increasing share of the joining, sealing, and bonding market.

Satisfying the Demand

Polymer films come in a variety of materials and forms, and
are used in applications ranging from industrial and agricultural to the
production of semiconductors and satellites. The worldwide demand for
high-performance films is still experiencing strong growth.1 Technical demands
are increasing all the time as application needs and customer requirements
drive a demand for higher performance. Typical performance demands include the
need for higher operating temperatures, improved abrasion resistance and
increased chemical resistance. This often means that the choice of materials
for tape substrates and films becomes restricted to a few high-performance
engineering polymers. This particular segment of the high-performance
engineering polymers market may be unfamiliar to engineers and designers.

Higher-performance engineering polymers can be defined as those that can operate
above 200°C (392°F) on a long-term basis. Several polymer materials fall into
this category, including VICTREX®
PEEKTM polymer, polytetrafluoroethylene (PTFE) and
polyimide (PI). The PEEK polymer has comparable performance properties to PTFE
and PI but provides some key combinations of properties not available in these
materials.

The PEEK product is a linear aromatic semi-crystalline polymer. It has a high
melting temperature of 343°C (649°F) and a glass-transition temperature of
143°C (289°F). The polymer combines this high-temperature performance with
excellent chemical resistance, mechanical performance, high purity, electrical
properties and good tribological behavior. It is used across many markets, from
semiconductor manufacturing and electronics to automotive and industrial
sectors.

PTFE was the first commercially available fluoropolymer, and has a melting
point of 330°C (626°F). The polymer is highly crystalline and non-polar, which
leads to very weak interactions between the polymer molecules. PTFE is a very
low-friction material but is also very soft and prone to creep under mechanical
load. PTFE has superb chemical resistance and is used in pipe and tank liners,
valves, and laboratory equipment. It is also widely used in friction and wear
applications across many industry segments.

Polyimide is an aromatic-based polymer with no glass transition or melting
temperature prior to decomposition of the polymer. Most polyimides are
classified as thermosets and are not melt-processable. The polymer displays a
very linear change in mechanical properties with temperature over a full
operating range. It also demonstrates excellent mechanical, electrical and
chemical performance over a range of temperatures, and is used extensively in
the semiconductor and electronics segment.

APTIV film features a range of properties that allow it to compete with
polyimide and PTFE tapes as a high-performance tape backing material.

Compared to polyimide (PI), these films offer:

Lower moisture absorption, which can adversely affect electrical
properties and make parts susceptible to thermal shock.

Two Victrex APTIV film high-performance pressure-sensitive tape systems are
available: an acrylic-based adhesive and a silicone-based adhesive. Both tapes
are available in 25, 50 and 125 µM (1.0, 2.0, and 5.0 mil) backing thickness
and a range of widths. A dynamic mix of properties makes these adhesives
well-suited for applications in areas including electronics, semiconductor,
automotive, aerospace, oil and gas, industrial, lighting, and batteries.

Benefits of APTIV film tape backing include high-temperature performance;
chemical and moisture resistance; excellent physical, mechanical and electrical
properties up to 260°C (500°F); adhesion to difficult-to-bond-to substrates
including polyimide and polyolefin; clean removability; and more. APTIV films
are FDA-compliant and halogen free; as a thermoplastic, they are also
recyclable and comply with RoHS. Capable of withstanding the higher processing
temperatures required when using lead-free solders, APTIV film serves as an
excellent masking material in electrical applications.

While both PTFE and polyimide will continue to be valuable options for use as
tape substrates, APTIV film provides engineers with an alternative choice to
PTFE or polyimide tapes. The development of these new substrates can also
provide a potential source of product development and performance enhancement
for the pressure-sensitive tape industry.

About the Company

Headquartered in the United Kingdom, Victrex plc
is an innovative leading manufacturer of high-performance materials used in a
variety of markets.

VICTREX® is a registered trademark of Victrex
Manufacturing Limited. PEEKTM,
PEEK-HTTM and APTIVTM are
trademarks of Victrex plc. VICOTE® is a registered trademark
of Victrex plc.

For more information on APTIV films, phone (800) VICTREX or visit www.victrex.com.

SIDEBAR: APTIV Film Performs in RFID Tags

When O.T.A.-Bieletro, a Brazilian company specializing in
solutions for identification and traceability, wanted a high-performance film
for the encapsulation of its RFID tags used on a truck manufacturing line, it
chose APTIV film based on VICTREX PEEK polymer. The film offers the ability to
withstand the extreme temperatures encountered during the vehicle’s painting
cycle without any loss in radio frequency signal reception capacity from the
device.

Encapsulating the RFID tags with APTIV film protects small components from the
aggressive environment of the truck’s production line and painting cycle. “This
is a new application for us,” explained O.T.A. Director Xavier Landmarks. “The
RFID labels encapsulated with the APTIV film performed beyond our expectations,
withstanding more than 10 painting cycles.
In addition, using the APTIV film allowed us to significantly reduce our
costs.”

The RFID tag is a thin sensor that is 0.5mm thick. It is affixed on each truck
chassis, where it remains for the entire production process. “The critical
point in the process is the painting line, during which the truck is exposed to
a very aggressive environment,” Landmarks said. “The challenge was to find a
material that is resistant to painting cycle temperatures of 180°C, 200°C and
220°C (356°F, 392°F, and 428°F). The tags are exposed to each of these
temperatures for one hour during the painting cycle. We needed a material
capable of withstanding at least five of these cycles without any imperfections
that might interfere with the readability of the labels.”

That material also required chemical resistance. “For example, it could not
contaminate the painting tanks by releasing particles or gases that could
contaminate the process,” Landmarks said. “It had to have low permeability and
be able to thermally isolate the internal components.”

John Getz, commercial leader of APTIV Films, said, “APTIV film is extremely
versatile and is used in a variety of high-performance automotive applications,
including wear-resistant bearings, sensor membranes, gaskets, adhesive tapes,
and now RFID devices. Its outstanding balance of chemical and wear resistance,
and its ability to withstand extreme temperatures, makes APTIV films a leading
choice for automotive-product designers.”

Products

The Handbook of Sealant Technology provides an in-depth examination of sealants, reviewing their historical developments and fundamentals, adhesion theories and properties, and today’s wide range of applications.